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Kokkinos V, Seimenis I. Concordance of verbal memory and language fMRI lateralization in people with epilepsy. J Neuroimaging 2024; 34:95-107. [PMID: 37968766 DOI: 10.1111/jon.13171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 10/29/2023] [Accepted: 11/01/2023] [Indexed: 11/17/2023] Open
Abstract
BACKGROUND AND PURPOSE This work investigates verbal memory functional MRI (fMRI) versus language fMRI in terms of lateralization, and assesses the validity of performing word recognition during the functional scan. METHODS Thirty patients with a diagnosis of epilepsy underwent verbal memory, visuospatial memory, and language fMRI. We used word encoding, word recognition, image encoding, and image recognition memory tasks, and semantic description, reading comprehension, and listening comprehension language tasks. We used three common lateralization metrics: network spatial distribution, maximum statistical value, and laterality index (LI). RESULTS Lateralization of signal spatial distribution resulted in poor similarity between verbal memory and language fMRI tasks. Signal maximum lateralization showed significant (>.8) but not perfect (1) similarity. Word encoding LI showed significant correlation only with listening comprehension LI (p = .016). Word recognition LI was significantly correlated with expressive language semantic description LI (p = .024) and receptive language reading and listening comprehension LIs (p = .015 and p = .019, respectively). There was no correlation between LIs of the visuospatial tasks and LIs of the language tasks. CONCLUSIONS Our results support the association between language and verbal memory lateralization, optimally determined by LI quantification, and the introduction of quantitative means for language fMRI interpretation in clinical settings where verbal memory lateralization is imperative.
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Affiliation(s)
- Vasileios Kokkinos
- Comprehensive Epilepsy Center, Northwestern Memorial Hospital, Chicago, Illinois, USA
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
- Department of Medicine, School of Health Sciences, Democritus University of Thrace, Alexandroupoli, Greece
| | - Ioannis Seimenis
- Department of Medicine, School of Health Sciences, Democritus University of Thrace, Alexandroupoli, Greece
- Medical School, National and Kapodistrian University of Athens, Athens, Greece
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Fleury M, Buck S, Binding LP, Caciagli L, Vos SB, Winston GP, Thompson P, Koepp MJ, Duncan JS, Sidhu MK. Episodic memory network connectivity in temporal lobe epilepsy. Epilepsia 2022; 63:2597-2622. [PMID: 35848050 PMCID: PMC9804196 DOI: 10.1111/epi.17370] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Temporal lobe epilepsy (TLE) affects brain networks and is associated with impairment of episodic memory. Temporal and extratemporal reorganization of memory functions is described in functional magnetic resonance imaging (fMRI) studies. Functional reorganizations have been shown at the local activation level, but network-level alterations have been underinvestigated. We aim to investigate the functional anatomy of memory networks using memory fMRI and determine how this relates to memory function in TLE. METHODS Ninety patients with unilateral TLE (43 left) and 29 controls performed a memory-encoding fMRI paradigm of faces and words with subsequent out-of-scanner recognition test. Subsequent memory event-related contrasts of words and faces remembered were generated. Psychophysiological interaction analysis investigated task-associated changes in functional connectivity seeding from the mesial temporal lobes (MTLs). Correlations between changes in functional connectivity and clinical memory scores, epilepsy duration, age at epilepsy onset, and seizure frequency were investigated, and between connectivity supportive of better memory and disease burden. Connectivity differences between controls and TLE, and between TLE with and without hippocampal sclerosis, were explored using these confounds as regressors of no interest. RESULTS Compared to controls, TLE patients showed widespread decreased connectivity between bilateral MTLs and frontal lobes, and increased local connectivity between the anterior MTLs bilaterally. Increased intrinsic connectivity within the bilateral MTLs correlated with better out-of-scanner memory performance in both left and right TLE. Longer epilepsy duration and higher seizure frequency were associated with decreased connectivity between bilateral MTLs and left/right orbitofrontal cortex (OFC) and insula, connections supportive of memory functions. TLE due to hippocampal sclerosis was associated with greater connectivity disruption within the MTL and extratemporally. SIGNIFICANCE Connectivity analyses showed that TLE is associated with temporal and extratemporal memory network reorganization. Increased bilateral functional connectivity within the MTL and connectivity to OFC and insula are efficient, and are disrupted by greater disease burden.
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Affiliation(s)
- Marine Fleury
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - Sarah Buck
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - Lawrence P. Binding
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
- Department of Computer Science, Centre for Medical Image ComputingUniversity College LondonLondonUK
| | - Lorenzo Caciagli
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
- Department of BioengineeringUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Sjoerd B. Vos
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
- Neuroradiological Academic Unit, University College London Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Gavin P. Winston
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
- Division of Neurology, Department of MedicineQueen's UniversityKingstonOntarioCanada
| | - Pamela J. Thompson
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - Matthias J. Koepp
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - John S. Duncan
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - Meneka K. Sidhu
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
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Bouyeure A, Bekha D, Patil S, Hertz-Pannier L, Noulhiane M. OUP accepted manuscript. Cereb Cortex Commun 2022; 3:tgac004. [PMID: 35261977 PMCID: PMC8895309 DOI: 10.1093/texcom/tgac004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 01/06/2022] [Accepted: 01/08/2022] [Indexed: 11/13/2022] Open
Abstract
The structure-function relationship between white matter microstructure and episodic memory (EM) has been poorly studied in the developing brain, particularly in early childhood. Previous studies in adolescents and adults have shown that episodic memory recall is associated with prefrontal-limbic white matter microstructure. It is unknown whether this association is also observed during early ontogeny. Here, we investigated the association between prefrontal-limbic tract microstructure and EM performance in a cross-sectional sample of children aged 4 to 12 years. We used a multivariate partial least squares correlation approach to extract tract-specific latent variables representing shared information between age and diffusion parameters describing tract microstructure. Individual projections onto these latent variables describe patterns of interindividual differences in tract maturation that can be interpreted as scores of white matter tract microstructural maturity. Using these estimates of microstructural maturity, we showed that maturity scores of the uncinate fasciculus and dorsal cingulum bundle correlated with distinct measures of EM recall. Furthermore, the association between tract maturity scores and EM recall was comparable between younger and older children. Our results provide new evidence on the relation between white matter maturity and EM performance during development.
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Affiliation(s)
- Antoine Bouyeure
- UNIACT, NeuroSpin, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
- UMR1141, Inserm, Université de Paris, 75019 Paris, France
| | - Dhaif Bekha
- UNIACT, NeuroSpin, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
- UMR1141, Inserm, Université de Paris, 75019 Paris, France
| | - Sandesh Patil
- UNIACT, NeuroSpin, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
- UMR1141, Inserm, Université de Paris, 75019 Paris, France
| | - Lucie Hertz-Pannier
- UNIACT, NeuroSpin, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
- UMR1141, Inserm, Université de Paris, 75019 Paris, France
| | - Marion Noulhiane
- UNIACT, NeuroSpin, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
- UMR1141, Inserm, Université de Paris, 75019 Paris, France
- Corresponding author: UNIACT, NeuroSpin, CEA, 91191 Gif-sur-Yvette, France.
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Sun YM, Peng YX, Wen Q, Dai Y, Liu XR, Yang XP, Ye Q. Resting-state fMRI in temporal lobe epilepsy patients with cognitive impairment: A protocol for systematic review and meta-analysis. Medicine (Baltimore) 2021; 100:e27249. [PMID: 34731102 PMCID: PMC8519237 DOI: 10.1097/md.0000000000027249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Temporal lobe epilepsy is a group of neurological diseases caused by the repeated abnormal discharge of brain neurons. Patients with this disease are often accompanied with cognitive impairment. However, the pathogenesis of the cognitive impairment remains unclear. Resting state functional magnetic resonance imaging is a kind of magnetic resonance imaging method based on blood oxygen level dependence. This can reflect the spontaneous brain functional activity of a human brain in the resting state. In recent years, a number of researchers have used resting state functional magnetic resonance imaging to study the changes in resting spontaneous brain function in patients with temporal lobe epilepsy with cognitive impairment (TLE-CI). However, due to the differences in sample and methodology, the results of these studies were inconsistent. Therefore, the present study aimed to investigate the characteristics of the resting spontaneous brain function in patients with TLE-CI through a meta-analysis. METHODS A search was conducted on electronic databases, including PubMed, Cochrane Library, EMBASE, Web of Science, China National Knowledge Infrastructure, WANGFANG DATA and Chinese Biomedical Literature Database, and Baidu scholar Database, from the establishment of the database to April 20, 2021. Randomized controlled trials that employed amplitude of low-frequency fluctuations/regional homogeneity to investigate the changes in resting spontaneous brain function in patients with TLE-CI were selected. Anisotropic effect size version of signed differential mapping was applied to perform the data analysis. RESULTS The study summarized the changes in spontaneous brain function in patients with TLE-CI. CONCLUSION The conclusion for the functional cerebral alterations based on the latest studies will be provided.
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Feasibility, Contrast Sensitivity and Network Specificity of Language fMRI in Presurgical Evaluation for Epilepsy and Brain Tumor Surgery. Brain Topogr 2021; 34:511-524. [PMID: 33837867 DOI: 10.1007/s10548-021-00839-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 03/30/2021] [Indexed: 02/05/2023]
Abstract
Language fMRI has become an integral part of the planning process in brain surgery. However, fMRI may suffer from confounding factors both on the patient side, as well as on the provider side. In this study, we investigate how patient-related confounds affect the ability of the patient to perform language fMRI tasks (feasibility), the task sensitivity from an image contrast point of view, and the anatomical specificity of expressive and receptive language fMRI protocols. 104 patients were referred for language fMRI in the context of presurgical procedures for epilepsy and brain tumor surgery. Four tasks were used: (1) a verbal fluency (VF) task to map vocabulary use, (2) a semantic description (SD) task to map sentence formation/semantic integration skills, (3) a reading comprehension (RC) task and (4) a listening comprehension (LC) task. Feasibility was excellent in the LC task (100%), but in the acceptable to mediocre range for the rest of the tasks (SD: 87.50%, RC: 85.57%, VF: 67.30%). Feasibility was significantly confounded by age (p = 0.020) and education level (p = 0.003) in VF, by education level (p = 0.004) and lesion laterality (p = 0.019) in SD and by age (p = 0.001), lesion laterality (p = 0.007) and lesion severity (p = 0.048) in RC. All tasks were comparable regarding sensitivity in generating statistically significant image contrast (VF: 90.00%, SD: 92.30%, RC: 93.25%, LC: 88.46%). The lobe of the lesion (p = 0.005) and the age (p = 0.009) confounded contrast sensitivity in the VF and SD tasks respectively. Both VF and LC tasks demonstrated unilateral lateralization of posterior language areas; only the LC task showed unilateral lateralization of anterior language areas. Our study highlights the effects of patient-related confounding factors on language fMRI and proposes LC as the most feasible, less confounded, and efficiently lateralizing task in the clinical presurgical context.
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Perrier J, Viard A, Levy C, Morel N, Allouache D, Noal S, Joly F, Eustache F, Giffard B. Longitudinal investigation of cognitive deficits in breast cancer patients and their gray matter correlates: impact of education level. Brain Imaging Behav 2020; 14:226-241. [PMID: 30406352 DOI: 10.1007/s11682-018-9991-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cognitive deficits are a major complaint in breast cancer patients, even before chemotherapy. Comprehension of the cerebral mechanisms related to cognitive impairment in breast cancer patients remains difficult due to the scarcity of studies investigating both cognitive and anatomical imaging changes. Furthermore, only some of the patients experienced cognitive decline following chemotherapy, yet few studies have identified risk factors for cognitive deficits in these patients. It has been shown that education level could impact cognitive abilities during the recovery phase following chemotherapy. Our main aim was to longitudinally evaluate cognitive and anatomical changes associated with cancer and chemotherapy in breast cancer patients. Our secondary aim was to assess the impact of education level on cognitive performances and gray matter (GM) atrophy in these patients. Twenty patients were included before chemotherapy (T1), 1 month (T2) and 1 year (T3) after chemotherapy. Twenty-seven controls without a history of cancer were assessed at T1 and T3 only. Cluster groups based on education level were defined for both groups and were further compared. Comparison between patients and controls revealed deficits in patients on verbal episodic memory retrieval at T1 and T3 and on executive functions at T3. After chemotherapy, breast cancer patients had GM atrophy that persisted or recovered 1 year after chemotherapy depending on the cortical areas. Increase in GM volumes from T1 to T3 were also found in both groups. At T2, patients with a higher level of education compared to lower level exhibited higher episodic memory retrieval and state anxiety scores, both correlating with cerebellar volume. This higher level of education group exhibited hippocampal atrophy. Our results suggest that, before chemotherapy, cancer-related processes impact cognitive functioning and that this impact seems exacerbated by the effect of chemotherapy on certain brain regions. Increase in GM volumes after chemotherapy were unexpected and warrant further investigations. Higher education level was associated, 1 month after the end of chemotherapy, with greater anxiety and hippocampal atrophy despite a lack of cognitive deficits. These results suggest, for the first time, the occurrence of compensation mechanisms that may be linked to cognitive reserve in relationship to state anxiety. This identification of factors, which may compensate cognitive impairment following chemotherapy, is critical for patient care and quality of life.
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Affiliation(s)
- Joy Perrier
- Normandie Univ, UNICAEN, PSL University, EPHE, INSERM, U1077, CHU de Caen, Neuropsychologie et Imagerie de la Mémoire Humaine, 14000, Caen, France.
| | - Armelle Viard
- Normandie Univ, UNICAEN, PSL University, EPHE, INSERM, U1077, CHU de Caen, Neuropsychologie et Imagerie de la Mémoire Humaine, 14000, Caen, France
| | - Christelle Levy
- Breast Committee Department, Centre François Baclesse, Caen, France
| | - Nastassja Morel
- Normandie Univ, UNICAEN, PSL University, EPHE, INSERM, U1077, CHU de Caen, Neuropsychologie et Imagerie de la Mémoire Humaine, 14000, Caen, France
| | | | - Sabine Noal
- Breast Committee Department, Centre François Baclesse, Caen, France
| | - Florence Joly
- Clinical Research Department, Caen, France.,Medical Oncology Department, CHU de Caen, Caen, France.,INSERM, U1086, ANTICIPE, Caen, France.,Cancer & Cognition, Platform, Ligue Contre le Cancer, CHU de Caen, Caen, France
| | - Francis Eustache
- Normandie Univ, UNICAEN, PSL University, EPHE, INSERM, U1077, CHU de Caen, Neuropsychologie et Imagerie de la Mémoire Humaine, 14000, Caen, France
| | - Bénédicte Giffard
- Normandie Univ, UNICAEN, PSL University, EPHE, INSERM, U1077, CHU de Caen, Neuropsychologie et Imagerie de la Mémoire Humaine, 14000, Caen, France.,Cancer & Cognition, Platform, Ligue Contre le Cancer, CHU de Caen, Caen, France
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Effects of highly purified cannabidiol (CBD) on fMRI of working memory in treatment-resistant epilepsy. Epilepsy Behav 2020; 112:107358. [PMID: 32871501 DOI: 10.1016/j.yebeh.2020.107358] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 01/08/2023]
Abstract
OBJECTIVE We aimed to determine changes in working memory and functional connectivity via functional magnetic resonance imaging (fMRI)-modified Sternberg task after treatment with highly purified cannabidiol (CBD, Epidiolex®; 100 mg/mL) in patients with treatment-resistant epilepsy (TRE). METHODS Twenty patients with TRE (mean age: 35.8 years; 7 male) performed fMRI Sternberg task before receiving CBD ("PRE") and after reaching stable dosage of CBD (15-25 mg/kg/day; "ON"). Each patient performed 2 runs of the modified Sternberg task during PRE and ON fMRI. Twenty-three healthy controls (HCs; mean age: 25 years; 11 M) also completed the task. All were presented with a sequence of 2 or 6 letters and instructed to remember them (encoding). After a delay, a single letter was shown, and participants recalled if letter was shown in sequence (retrieval). Paired t-tests were used to analyze accuracy/response times. For each subject, event-related modeling of encoding (2 and 6 letters) and retrieval was performed. Paired t-tests controlling for seizure frequency change and scanner type were performed to assess changes in neural recruitment during encoding and retrieval in key regions of interest. RESULTS There was nonsignificant increase in mean modified Sternberg task accuracy from PRE to ON-CBD (28.6 vs. 32.1%). PRE and ON accuracy was worse than HCs (75.5%, p < 0.001). ON-PRE comparison revealed increased activation in the right inferior frontal gyrus (IFG) during 6-letter encoding. ON-HC comparison revealed increased activation in bilateral IFG and insula during 2-letter encoding. PRE-HC comparison revealed decreased activation in the left middle frontal gyrus during 6-letter encoding. None of these activations were associated with working memory performance. SIGNIFICANCE Treatment-resistant epilepsy results in poorer working memory performance and lower neural recruitment compared with HCs. Treatment with CBD results in no significant changes in working memory performance and in significant increases in neural activity in regions important for verbal memory and attention compared with HCs during memory encoding.
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Buck S, Bastos F, Baldeweg T, Vargha-Khadem F. A Functional MRI Paradigm Suitable for Language and Memory Mapping in Pediatric Temporal Lobe Epilepsy. Front Neurol 2020; 10:1384. [PMID: 31998226 PMCID: PMC6966885 DOI: 10.3389/fneur.2019.01384] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/16/2019] [Indexed: 11/13/2022] Open
Abstract
Functional Magnetic Resonance Imaging (fMRI) is a technique frequently used to determine the territories of eloquent tissue that serve critical functions, such as language. This can be particularly useful as part of the pre-surgical assessment for temporal lobe epilepsy (TLE) in order to predict cognitive outcome and guide surgical decision-making. Whereas language fMRI is widely used, memory fMRI is less frequently employed in adult TLE, and lacking in childhood TLE. We have developed a combined language/memory fMRI paradigm that is suitable for children, to provide clinically useful information for surgical planning in pediatric TLE. We evaluated this paradigm in 28 healthy children, aged 8 to 18 years. The advantages of this paradigm are: (a) it examines the functional mapping of language and memory networks within one scanning session, (b) provides assessment of both memory encoding- and retrieval-related neural networks, (c) examines recall-based retrieval to engage hippocampal involvement compared to recognition-based retrieval, and (d) provides overt verbal responses to monitor in-scanner memory performance. This novel fMRI paradigm was designed for language and memory mapping in pediatric TLE and could provide clinically useful information for surgical planning. Finally, parallel versions of the paradigm allow the comparison of brain activations pre- and post-surgical intervention.
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Affiliation(s)
- Sarah Buck
- Cognitive Neuroscience and Neuropsychiatry Section, Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- Great Ormond Street Hospital for Children National Health Service Trust, London, United Kingdom
| | - Filipa Bastos
- Cognitive Neuroscience and Neuropsychiatry Section, Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- Great Ormond Street Hospital for Children National Health Service Trust, London, United Kingdom
- Unit of Paediatric Neurology and Neurorehabilitation, Woman-Mother-Child Department, Lausanne University Hospital, Lausanne, Switzerland
| | - Torsten Baldeweg
- Cognitive Neuroscience and Neuropsychiatry Section, Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- Great Ormond Street Hospital for Children National Health Service Trust, London, United Kingdom
| | - Faraneh Vargha-Khadem
- Cognitive Neuroscience and Neuropsychiatry Section, Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- Great Ormond Street Hospital for Children National Health Service Trust, London, United Kingdom
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Buck S, Sidhu MK. A Guide to Designing a Memory fMRI Paradigm for Pre-surgical Evaluation in Temporal Lobe Epilepsy. Front Neurol 2020; 10:1354. [PMID: 31998216 PMCID: PMC6962296 DOI: 10.3389/fneur.2019.01354] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/09/2019] [Indexed: 12/05/2022] Open
Abstract
There has been increasing interest in the clinical and experimental use of memory functional Magnetic Resonance Imaging (fMRI). The 2017 American Academy of Neurology practice guidelines on the use of pre-surgical cognitive fMRI suggests that verbal memory fMRI could be used to lateralize memory functions in people with Temporal Lobe Epilepsy (TLE) and should be used to predict post-operative verbal memory outcome. There are however technical and methodological considerations, to optimize both the sensitivity and specificity of this imaging modality. Below we discuss these constraints and suggest recommendations to consider when designing a memory fMRI paradigm.
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Affiliation(s)
- Sarah Buck
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology of Neurology, London, United Kingdom
- Epilepsy Society MRI Unit, Chalfont Saint Peter, United Kingdom
| | - Meneka K. Sidhu
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology of Neurology, London, United Kingdom
- Epilepsy Society MRI Unit, Chalfont Saint Peter, United Kingdom
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Encoding and immediate retrieval tasks in patients with epilepsy: A functional MRI study of verbal and visual memory. J Neuroradiol 2018; 45:157-163. [DOI: 10.1016/j.neurad.2018.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 12/26/2017] [Accepted: 02/08/2018] [Indexed: 11/30/2022]
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In Reply to "Selective Amygdalohippocampectomy for Mesial Temporal Sclerosis: Special Considerations in Geniuses". World Neurosurg 2018; 111:431-432. [PMID: 29499601 DOI: 10.1016/j.wneu.2017.12.074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Accepted: 12/11/2017] [Indexed: 11/23/2022]
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Imaging memory and predicting postoperative memory decline in temporal lobe epilepsy: Insights from functional imaging. Rev Neurol (Paris) 2015; 171:307-14. [PMID: 25726354 DOI: 10.1016/j.neurol.2014.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/23/2014] [Accepted: 12/29/2014] [Indexed: 11/24/2022]
Abstract
After medial temporal lobe epilepsy (MTLE) surgery, there is considerable individual variation in the extent, nature and direction of postoperative memory change. Before surgery, epileptic patients who are surgery candidates need precise information about the potential cognitive after effects, and particularly in temporal lobe epilepsy, postoperative memory changes. Clinical and neuropsychological data may bring useful information to predict the postoperative memory outcome, but, these data are not always sufficient to replace the Wada test, considered for a long time, as the gold standard to predict postoperative decline following surgery. In any case, numerous studies demonstrate that the Wada procedure can be nowadays reliably replaced by functional MRI (fMRI) activation studies. A vast majority of fMRI studies suggest that it is the functional adequacy of the resected hippocampus rather than the functional reserve of the contralateral hippocampus that determines the extent of postoperative memory decline. In addition, new functional neuroimaging procedures that explore more widespread network disruptions commonly found in MTLE such as diffusion-tensor imaging (DTI) or connectivity studies could in the future constitute a reliable approach combined with fMRI activation studies to significantly improve the prediction of postsurgical memory decline.
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Memory Assessment in the Clinical Context Using Functional Magnetic Resonance Imaging. Neuroimaging Clin N Am 2014; 24:585-97. [DOI: 10.1016/j.nic.2014.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Abstract
Although Alzheimer's disease (AD) is a common cause of memory impairment and dementia in the elderly disturbed memory function is a widespread subjective and/or objective symptom in a variety of medical conditions. The early detection and correct distinction of AD from non-AD memory impairment is critically important to detect possibly treatable and reversible underlying causes. In the context of clinical research, it is crucial to correctly distinguish between AD or non-AD memory impairment in order to build homogenous study populations for the assessment of new therapeutic possibilities. The distinction of AD from non-AD memory impairment may be difficult, especially in mildly affected patients, due to an overlap of clinical symptoms and biomarker alterations between AD and certain non-AD conditions. This review aims to describe recent aspects of the differential diagnosis of AD and non-AD related memory impairment and how these may be considered in the presence of memory deficits.
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Affiliation(s)
- Sönke Arlt
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Gupta L, Besseling RMH, Overvliet GM, Hofman PAM, de Louw A, Vaessen MJ, Aldenkamp AP, Ulman S, Jansen JFA, Backes WH. Spatial heterogeneity analysis of brain activation in fMRI. NEUROIMAGE-CLINICAL 2014; 5:266-76. [PMID: 25161893 PMCID: PMC4141984 DOI: 10.1016/j.nicl.2014.06.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In many brain diseases it can be qualitatively observed that spatial patterns in blood oxygenation level dependent (BOLD) activation maps appear more (diffusively) distributed than in healthy controls. However, measures that can quantitatively characterize this spatial distributiveness in individual subjects are lacking. In this study, we propose a number of spatial heterogeneity measures to characterize brain activation maps. The proposed methods focus on different aspects of heterogeneity, including the shape (compactness), complexity in the distribution of activated regions (fractal dimension and co-occurrence matrix), and gappiness between activated regions (lacunarity). To this end, functional MRI derived activation maps of a language and a motor task were obtained in language impaired children with (Rolandic) epilepsy and compared to age-matched healthy controls. Group analysis of the activation maps revealed no significant differences between patients and controls for both tasks. However, for the language task the activation maps in patients appeared more heterogeneous than in controls. Lacunarity was the best measure to discriminate activation patterns of patients from controls (sensitivity 74%, specificity 70%) and illustrates the increased irregularity of gaps between activated regions in patients. The combination of heterogeneity measures and a support vector machine approach yielded further increase in sensitivity and specificity to 78% and 80%, respectively. This illustrates that activation distributions in impaired brains can be complex and more heterogeneous than in normal brains and cannot be captured fully by a single quantity. In conclusion, heterogeneity analysis has potential to robustly characterize the increased distributiveness of brain activation in individual patients. A number of spatial heterogeneity measures of activation maps were explored in children with Rolandic epilepsy and language impairment Proposed measures capture the complexity, shape and distribution of brain activation patterns For a language task all proposed measures revealed that patients exhibit more heterogeneous activation patterns than controls, whereas for a motor task no differences appeared Spatial heterogeneity of activation patterns is a complex feature that cannot be captured by one single measure, but shape and lacunarity represented the best descriptive measures
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Affiliation(s)
- Lalit Gupta
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - René M H Besseling
- Epilepsy Center Kempenhaeghe, Heeze, The Netherlands ; Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Geke M Overvliet
- Epilepsy Center Kempenhaeghe, Heeze, The Netherlands ; Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands ; Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Paul A M Hofman
- Epilepsy Center Kempenhaeghe, Heeze, The Netherlands ; Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands ; Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Anton de Louw
- Epilepsy Center Kempenhaeghe, Heeze, The Netherlands
| | - Maarten J Vaessen
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands ; Epilepsy Center Kempenhaeghe, Heeze, The Netherlands ; Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Albert P Aldenkamp
- Epilepsy Center Kempenhaeghe, Heeze, The Netherlands ; Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Shrutin Ulman
- Philips Research, Philips Electronics India Ltd., Manyata Tech. Park, Bangalore, India
| | - Jacobus F A Jansen
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands ; Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Walter H Backes
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands ; Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands
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17
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Kalpouzos G, Fischer H, Rieckmann A, Macdonald SWS, Bäckman L. Impact of negative emotion on the neural correlates of long-term recognition in younger and older adults. Front Integr Neurosci 2012; 6:74. [PMID: 23049503 PMCID: PMC3445868 DOI: 10.3389/fnint.2012.00074] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 08/26/2012] [Indexed: 12/31/2022] Open
Abstract
Some studies have suggested that the memory advantage for negative emotional information over neutral information (“negativity effect”) is reduced in aging. Besides the fact that most findings are based on immediate retrieval, the neural underpinnings of long-term emotional memory in aging have so far not been investigated. To address these issues, we assessed recognition of neutral and negative scenes after 1- and 3-week retention intervals in younger and older adults using functional magnetic resonance imaging. We further used an event-related design in order to disentangle successful, false, and true recognition. This study revealed four key findings: (1) increased retention interval induced an increased rate of false recognitions for negative scenes, canceling out the negativity effect (present for hit rates only) on discrimination in both younger and older adults; (2) in younger, but not older, adults, reduced activity of the medial temporal lobe was observed over time for neutral scenes, but not for negative scenes, where stable or increased activity was seen; (3) engagement of amygdala (AMG) was observed in older adults after a 3-week delay during successful recognition of negative scenes (hits vs. misses) in comparison with neutral scenes, which may indicate engagement of automatic processes, but engagement of ventrolateral prefrontal cortex was unrelated to AMG activity and performance; and (4) after 3 weeks, but not after 1 week, true recognition of negative scenes was characterized by more activity in left hippocampus and lateral occipito-temporal regions (hits vs. false alarms). As these regions are known to be related to consolidation mechanisms, the observed pattern may indicate the presence of delayed consolidation of true memories. Nonetheless, older adults’ low performance in discrimination of negative scenes could reflect the fact that overall, after long delays of retention, they rely more on general information rather than on perceptual detail in making recognition judgments.
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Affiliation(s)
- Grégoria Kalpouzos
- Aging Research Center, Karolinska Institute and Stockholm University Stockholm, Sweden
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18
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Fehr T, Wallace GL, Erhard P, Herrmann M. The neural architecture of expert calendar calculation: a matter of strategy? Neurocase 2011; 17:360-71. [PMID: 21547846 DOI: 10.1080/13554794.2010.532135] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Savants and prodigies are individuals with exceptional skills in particular mental domains. In the present study we used functional magnetic resonance imaging to examine neural correlates of calendar calculation in two individuals, a savant with Asperger's disorder and a self-taught mathematical prodigy. If there is a modular neural organization of exceptional performance in a specific mental domain, calendar calculation should be reflected in a considerable overlap in the recruitment of brain circuits across expert individuals. However, considerable individual differences in activation patterns during calendar calculation were noted. The present results indicate that activation patterns produced by complex mental processing, such as calendar calculation, seem to be influenced strongly by learning history and idiosyncratic strategy usage rather than a modular neural organization. Thus, well-known individual differences in complex cognition play a major role even in experts with exceptional abilities in a particular mental domain and should in particular be considered when examining the neural architecture of complex mental processes and skills.
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Affiliation(s)
- Thorsten Fehr
- Center for Cognitive Sciences, Department of Neuropsychology and Behavioral Neurobiology, University of Bremen, Bremen, Germany.
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19
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Vlooswijk MC, Jansen JF, de Krom MC, Majoie HM, Hofman PA, Backes WH, Aldenkamp AP. Functional MRI in chronic epilepsy: associations with cognitive impairment. Lancet Neurol 2010; 9:1018-27. [PMID: 20708970 DOI: 10.1016/s1474-4422(10)70180-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chronic epilepsy is frequently accompanied by serious cognitive side-effects. Clinical factors are important, but cannot account entirely for this cognitive comorbidity. Therefore, research is focusing on the underlying cerebral mechanisms to understand the development of cognitive dysfunction. In the past two decades, functional MRI techniques have been applied extensively to the study of cognitive impairment in chronic epilepsy. However, because of wide variation in study designs, analysis methods, and data presentation, interpretation of these studies has become increasingly difficult for clinicians. In patients with localisation-related epilepsy, whether findings of functional MRI represent the underlying neuronal substrate for cognitive decline remains a subject of debate.
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Affiliation(s)
- Marielle Cg Vlooswijk
- Department of Neurology, Maastricht University Medical Centre, Maastricht, Netherlands
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20
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Dupont S, Duron E, Samson S, Denos M, Volle E, Delmaire C, Navarro V, Chiras J, Lehéricy S, Samson Y, Baulac M. Functional MR Imaging or Wada Test: Which Is the Better Predictor of Individual Postoperative Memory Outcome? Radiology 2010; 255:128-34. [PMID: 20308450 DOI: 10.1148/radiol.09091079] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sophie Dupont
- Epilepsy Unit, Neurology Clinic Paul Castaigne, Hôpital de la Pitié-Salpêtrière, APHP, 47 boulevard de l'Hôpital, 75651 Paris cedex 13, France.
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21
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Eliassen JC, Holland SK, Szaflarski JP. Compensatory brain activation for recognition memory in patients with medication-resistant epilepsy. Epilepsy Behav 2008; 13:463-9. [PMID: 18611446 PMCID: PMC2609901 DOI: 10.1016/j.yebeh.2008.06.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2008] [Revised: 06/18/2008] [Accepted: 06/19/2008] [Indexed: 11/19/2022]
Abstract
Progressive decline of memory functions has been observed in patients with chronic medication-resistant epilepsy. The progression likely relates to the effects of epileptiform discharges, seizures, and medications on the processes of encoding and retrieval. The goal of the study described here was to use functional MRI (fMRI) to examine the effects of chronic epilepsy on verbal recognition memory. We enrolled 12 patients with medication-resistant epilepsy (5 with right and 7 with left hemispheric seizure onset) and 18 healthy controls matched for age, gender, and handedness. Subjects underwent fMRI at 3T using a word recognition task during which they had to recall if words presented during scanning were words they had learned prior to scanning. Although we noted many similarities in the fMRI activation patterns between the subjects with epilepsy and the healthy subjects in areas typically involved in memory processing, testing of the interaction effects for target-foil differences between groups revealed several differences in activation including the right insula, the left cuneus, and the bilateral subgenual anterior cingulate cortex (ACC). In patients with epilepsy, these regions exhibited greater activation for targets than foils, but in healthy subjects the difference was reversed (right insula), absent (left cuneus), or included deactivation to target words (pregenual ACC). These differences were seen despite similar performance during the memory task, suggesting that activations observed in these additional regions may represent compensatory processes for verbal recognition memory that are induced by chronic brain injury related to recurrent seizures.
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Affiliation(s)
- James C. Eliassen
- Center for Imaging Research, Cincinnati Epilepsy Center, University of Cincinnati Academic Health Center, Cincinnati, OH
- Department of Psychiatry, Cincinnati Epilepsy Center, University of Cincinnati Academic Health Center, Cincinnati, OH
| | - Scott K. Holland
- Imaging Research Center and Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Jerzy P. Szaflarski
- Center for Imaging Research, Cincinnati Epilepsy Center, University of Cincinnati Academic Health Center, Cincinnati, OH
- Department of Neurology, Cincinnati Epilepsy Center, University of Cincinnati Academic Health Center, Cincinnati, OH
- The Neuroscience Institute, Cincinnati, OH, USA
- Address for correspondence: Jerzy P. Szaflarski, MD, PhD; University of Cincinnati Academic Health Center; Department of Neurology; 260 Stetson Street, Rm. 2350; ML 0525; Cincinnati, OH 45267-0525; E-mail: ; Phone: 513.558.4050
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22
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McDonald CR. The use of neuroimaging to study behavior in patients with epilepsy. Epilepsy Behav 2008; 12:600-11. [PMID: 18078790 PMCID: PMC2702661 DOI: 10.1016/j.yebeh.2007.10.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Accepted: 10/31/2007] [Indexed: 10/22/2022]
Abstract
Structural and functional neuroimaging continues to play an increasing role in the presurgical evaluation of patients with epilepsy. In addition to its value in localizing the epileptogenic zone and eloquent cortex, neuroimaging is contributing to our understanding of mood comorbidity in epilepsy. Although the vast majority of research has focused on patients with temporal lobe epilepsy (TLE), neuroimaging studies of patients with extratemporal epilepsy and primary generalized epilepsy are increasing in number. In this review, structural and functional imaging modalities that have received considerable research attention in recent years are reviewed, and their strengths and limitations for understanding behavior in epilepsy are assessed. In addition, advances in multimodal imaging are discussed along with their potential application to the presurgical evaluation of patients with seizure disorders.
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Affiliation(s)
- Carrie R. McDonald
- Department of Psychiatry, University of California, San Diego, Multimodal Imaging Laboratory, University of California, San Diego
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24
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Bosshardt S, Schmidt CF, Jaermann T, Degonda N, Boesiger P, Nitsch RM, Hock C, Henke K. Effects of memory consolidation on human hippocampal activity during retrieval. Cortex 2005; 41:486-98. [PMID: 16042025 DOI: 10.1016/s0010-9452(08)70189-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Day-to-day memories undergo transformation from short-term to long-term storage, a process called memory consolidation. Animal studies showed that memory consolidation requires protein synthesis and the growth of new hippocampal synapses within 24 h. To test for effects of memory consolidation in the human, we examined brain activation during the retrieval of information at 10 min and at 24 h following learning using functional magnetic resonance imaging (fMRI), an indirect measure of synaptic activity. Learning instructions were adjusted to yield a comparable retrieval quantity and retrieval quality at 10 min and 24 h after learning. The left hippocampal formation exhibited enhanced activity during the retrieval at the 24 h lag compared to the retrieval at the 10 min lag. Moreover, the activity in the left anterior hippocampal formation showed stronger correlations with retrieval quantity and retrieval quality at the 24 h lag than at the 10 min lag. This suggests that the relation between left anterior hippocampal activity and retrieval success became closer as consolidation progressed. These fMRI results in the human hippocampal formation may correspond to the neurobiological results in the animal hippocampal formation of a strengthening and growth of synaptic connections within 24 h.
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Affiliation(s)
- Simone Bosshardt
- Division of Psychiatry Research, University of Zurich, Zurich, Switzerland
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25
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Boddaert N, Barthélémy C, Poline JB, Samson Y, Brunelle F, Zilbovicius M. Autism: functional brain mapping of exceptional calendar capacity. Br J Psychiatry 2005; 187:83-6. [PMID: 15994576 DOI: 10.1192/bjp.187.1.83] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND 'Autistic savants' are individuals with autism who have extraordinary skills. Brain mechanisms underlying such capacities are still unknown. AIMS To map the exceptional calendar capacity of a man with primary autism. METHOD Positron emission tomography was used to map brain activity in a man who is able to associate a day of the week with the corresponding calendar date. RESULTS During the calendar task, the left hippocampus, the left frontal cortex and the left middle temporal lobe were activated. CONCLUSIONS The cerebral circuit involved in this man's prodigious calendar skill is similar to that normally involved in memory retrieval tasks. These results suggest that the prodigious capacities may be sustained by memory processing.
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Affiliation(s)
- Nathalie Boddaert
- Service Hospitalier Frédéric Joliot, DRM, DSV, CEA, 4 Place du General Leclerc 91406, Orsay, France
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26
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Leijten FSS, Alpherts WCJ, Van Huffelen AC, Vermeulen J, Van Rijen PC. The Effects on Cognitive Performance of Tailored Resection in Surgery for Nonlesional Mesiotemporal Lobe Epilepsy. Epilepsia 2005; 46:431-9. [PMID: 15730541 DOI: 10.1111/j.0013-9580.2005.33604.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE Mesiotemporal lobe epilepsy (MTLE) can be treated with different surgical approaches. In tailored resections, neocortex is removed beyond "standard" margins when spikes are present in the electrocorticogram. We hypothesized that these larger resections are justified because spiking neocortex is dysfunctional. This would imply that in patients with spikes (a) postoperative cognitive performance is not affected, and (b) preoperative performance is worse than without spikes. METHODS We studied 80 operated-on MTLE patients with pathologically confirmed nonlesional hippocampal sclerosis. All patients were left-sided language dominant and underwent cognitive tests 6 months pre- and postoperatively. A repeated measures analysis of variance (ANOVA) was performed, looking for within- and between-subjects interactions with presence of intraoperative neocortical spikes. RESULTS Intraoperatively, neocortical spikes were present in 61% of patients. Improved postoperative cognitive outcome was seen only in left-sided patients with spikes. Their performance IQ (PIQ) increased by 8.1 points (95% confidence interval, 3.8-12.3; p = 0.02), and visual naming latency by 12.8 s (95% CI, 2.1-23.5; p = 0.07). Conversely, in left-sided patients without spikes, naming latency declined by 7.5 s (95% CI, -2.3-17.2; p = 0.07). Preoperative scores were comparable except for a 15.3-point (95% CI, 0.1-30.5; p = 0.02) lower VIQ in left-sided patients without spikes. CONCLUSIONS Tailoring does not harm cognitive performance and is, in left-sided MTLE, associated with postoperative improvement. Left-sided MTLE without neocortical spikes has lower verbal scores, which tend to decline after standard resection and may represent a special pathophysiologic entity.
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Affiliation(s)
- Frans S S Leijten
- Rudolf Magnus Institute of Neuroscience, Department of Clinical Neurophysiology, University Medical Center Utrecht, Utrecht, The Netherlands.
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Powell HWR, Koepp MJ, Richardson MP, Symms MR, Thompson PJ, Duncan JS. The application of functional MRI of memory in temporal lobe epilepsy: a clinical review. Epilepsia 2004; 45:855-63. [PMID: 15230713 DOI: 10.1111/j.0013-9580.2004.41603.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Functional MRI (fMRI) is a useful tool for noninvasively localizing areas in the brain involved in specific cognitive functions. Since its introduction, there has been considerable speculation regarding the role it may play in the presurgical assessment of temporal lobe epilepsy (TLE). This review considers the progress made to date in using fMRI to investigate memory processing in the medial temporal lobe in normal subjects and in those with TLE. Results so far suggest that fMRI will be incorporated into the presurgical assessment of TLE in the coming years to improve definition of eloquent cerebral areas, with the objective of minimizing the adverse cognitive sequelae of anterior temporal lobe resection.
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Affiliation(s)
- H W Robert Powell
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College of London and MRI Unit, National Society for Epilepsy, Buckinghamshire, U.K.
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Lespinet-Najib V, N'Kaoua B, Sauzéon H, Bresson C, Rougier A, Claverie B. Levels of processing with free and cued recall and unilateral temporal lobe epilepsy. BRAIN AND LANGUAGE 2004; 89:83-90. [PMID: 15010240 DOI: 10.1016/s0093-934x(03)00303-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/28/2003] [Indexed: 05/24/2023]
Abstract
This study investigates the role of the temporal lobes in levels-of-processing tasks (phonetic and semantic encoding) according to the nature of recall tasks (free and cued recall). These tasks were administered to 48 patients with unilateral temporal epilepsy (right "RTLE"=24; left "LTLE"=24) and a normal group (n=24). The results indicated that LTLE patients were impaired for semantic processing (free and cued recall) and for phonetic processing (free and cued recall), while for RTLE patients deficits appeared in free recall with semantic processing. It is suggested that the left temporal lobe is involved in all aspects of verbal memory, and that the right temporal lobe is specialized in semantic processing. Moreover, our data seem to indicate that RTLE patients present a retrieval processing impairment (semantic condition), whereas the LTLE group is characterized by encoding difficulties in the phonetic and semantic condition.
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Affiliation(s)
- Véronique Lespinet-Najib
- Laboratoire de Neuropsychologie Expérimentale, Université Victor Segalen Bordeaux 2, Bordeaux, France.
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Vingerhoets G, Deblaere K, Backes WH, Achten E, Boon P, Boon PJ, Hofman P, Vermeulen J, Vonck K, Wilmink J, Aldenkamp AP. Lessons for neuropsychology from functional MRI in patients with epilepsy. Epilepsy Behav 2004; 5 Suppl 1:S81-9. [PMID: 14725851 DOI: 10.1016/j.yebeh.2003.11.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This contribution aims to review the major findings of pre- and postsurgical functional magnetic resonance imaging (fMRI) in patients with refractory epilepsy from a neuropsychological perspective. We compared the contribution of fMRI with the intracarotid amytal procedure (IAP) with respect to functional mapping of language and memory in patients with therapy-resistant epilepsy. We conclude that using comprehensive language paradigms, fMRI has been able (1) to provide estimates of the degree of language lateralization including the degree of involvement of the nondominant hemisphere, (2) to provide information on the location of its activated network during expressive and receptive language, and (3) to help delineate eloquent language regions in the vicinity of the surgical target, thus preventing postoperative complications. The contribution of the frequently observed nondominant hemisphere activation to language should be explored and its clinical relevance determined. Evidence from fMRI studies is accumulating that reorganization of cognitive and motor function favors the activation of contralateral homotopic areas, although this process is far from understood. The exact functional contribution of atypical areas of activation should be investigated critically. In the presurgical evaluation process, detailed and reliable localization of language and memory functions of the individual patient is mandatory and should be the ultimate goal in the development of comprehensive clinical fMRI protocols.
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Affiliation(s)
- Guy Vingerhoets
- Laboratory for Neuropsychology, Ghent University, De Pintelaan 185, B-9000 Ghent, Belgium.
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Abstract
The impact of advanced brain imaging procedures in the field of human memory disorder is reviewed, with particular emphasis on current and potential applications that may impact upon the diagnosis and management of memory-disordered patients. While both advanced structural, resting physiological and functional physiological brain imaging procedures have been applied to conditions where memory disorder is a major feature, the specific implications of research findings for diagnosis and treatment in routine clinical practice remain tentative and promising, but not yet substantive enough to inform clinical decisions to a significant degree. In terms of diagnostic applications, several promising areas include dementia, epilepsy, and transient amnesic states. In the case of applications in treatment settings, advanced brain imaging procedures may help to monitor neural correlates of spontaneous recovery or progression of memory function, and may also help in the planning and monitoring of therapeutic intervention.
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Affiliation(s)
- Narinder Kapur
- Wessex Neurological Centre, Department of Psychology, University of Southampton, UK.
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